Central Door Locking - Peter Groom

I have a Seat Cordoba, unfortunately without Central Door locking or any alarm.
Id like to investegate fitting Central Door Locking to it.
Any words of wisdom about any unforseen problems or where to purchase the unit from.

The main dealer isnt keen and quoted over £400.

Many Thanks

NB Im technically competent, without being a physics genius!
Central Door Locking - Dynamic Dave
Maplin do a DIY central locking kit.
Central Door Locking - Andrew-T
Four-door plus tailgate kits are certainly available for about £50. I found a supplier within 10 miles by asking at a Peugeot dealer. A bit fiddly to fit, but worth the experience.
Central Door Locking - Gen
I bought one from Maplin a week or two ago. Reduced from 49.99 to 19.99. Get in there quick! Special offer. Haven't fitted yet though. It's four doors, no tailgate set

Value my car